110 .American Fisheries Society 



with magnificent possibilities for the betterment of hu- 

 manity, they are incomplete of themselves and fall far short 

 of yielding the greatest possible returns, until the cause of 

 "fish culture" is inseparably associated with them. Con- 

 servation has had her Pinchot, reclamation her Carey. 

 Who will rise up and champion the cause of irrigational fish 

 culture ? 



DISCUSSION 



Mr. Thompson : This is to some extent a new subject, particularly 

 so to many of the members of the Society now before me who have 

 never had the opportunity and privilege of working in the irrigation 

 regions, and who, therefore, are not as familiar with the matter as I 

 would like. Hence a full and free discussion, which I urgently solicit, 

 will be especially helpful to us all. 



Prof. L. L. Dyche, Pratt, Kan. : I understood the gentleman to 

 say that it was not possible to regulate the outgoing of fish into these 

 irrigation ditches by the use of wire screen nets. Is that right? 



Mr. \\'. T. Thompson. Fairport, Iowa: That was Dr. Jordan's 

 statement, and I endorse it as correct. 



Professor Dyche: I do not know just what your conditions are, 

 but 1 do nut have any difficulty in managing fish with wire screens. All 

 the ponds in the new hsh hatchery for Kansas will be connected by 

 water-ways that are two feet nine inches wide, and we expect to man- 

 age the fish, keeping them out or letting them go into certain places, 

 by wire screens. These screens are made in sections, some 500 of them 

 in all. Those with 3-inch mesh wire are used to keep out coarse stuff, 

 as weeds, brush, moss and wood. Other screens are used as conditions 

 may demand and are made of one-inch, one-half-inch or one-quarter- 

 inch mesh wire. One or more of the screens may be used at the same 

 time. If small fish are to lie controlled the mesh may be as small as 

 that used in window screens. We have experimented some, and have 

 had no trouble in keeping out trash, weeds and grass by regulating" it 

 with different sized screens. One of the men who has charge of the 

 hatchery grounds goes around, lifts screens and takes out trash; and 

 we do not understand why you cannot keep trash out of irrigating 

 ditches if you will build a cement structure in which the screens of 

 different sized mesh can be fitted, and thus c< ntrol both trash and fish 

 in the ditches. I do not see why both fish and trash cannot be managed 

 if you put in proper screens. Such a system may need a little care, but 

 it seems to me that it can be successfully operated. 



Mr. Thompson : Where was it you were making these experiments? 



Professor Dyche: In Kansas. I have a paper bearing on the sub- 

 ject and I will present the matter later in my paper, with accompanying 

 blueprints. 



